"Dry Leafing" – how to sanitize?

[user 214470]

There is a commercial Estonian beer called "Sauna session", it pretty much tastes like sauna in a bottle (super nice). I want to brew something similar. I talked to the guys from that same brewery during one "beer expo" and they said they make birch leaf tea and add it at the end of boil. I tried it last time and I could barely taste any birch in completed beer. The smell of the tea was wonderful though. Oh, and the birch leaf tea is super bitter, it also added unwanted "astringent bitterness" to the beer.

This time, I'm thinking of adding dried birch leaves to the secondary – identical to dry hopping. I'm thinking I would get maximum aroma this way, without that astringent bitterness. The question though - how do I sanitize dry birch leaves? I guess I can't just dump them in without sanitizing? I know there's vodka, but I would need much of it to sanitize 3 oz dried leaves, I don't want to add much vodka in this beer... What about the oven? What would be the lowest heat/time to make sure the leaves don't start an infection? (I don't want to heat them too much either, so I don't drive off the aroma...)

 

[Craigmn]

Just dip in sanitizer

 

[user 214470]

Like StarSan? Nothing harmful about such method?
One thing though – with green leaves I would be cool with it, but with dry leaves – they will soak up pretty good amount of sanitizer...

 

[MrPowers]

Like StarSan? Nothing harmful about such method?
One thing though – with green leaves I would be cool with it, but with dry leaves – they will soak up pretty good amount of sanitizer...

You could do it that way.

However, I would steam them briefly over a pot of boiling water. You may loose a little bit of flavor/aroma. But it would be a better way to make sure they were relatively sanitized and you wouldn’t introduce too much star San.

 

[Aaron Beers]

I would suggest you make the birch leaf tea in the same way you would make iced tea, e.g. add the leaves to water and store it in the fridge for a few days. Then before you intend to add it to your beer, add an appropriate amount of campden/sulfite to it to kill any micro ogranisms in it and let it off gas for 24 hours before adding it.

 

[bucketnative]

Muddle in vodka, add whole lot - leaves and vodka - to beer. That's how I have done basil and mint.

 

[user 214470]

Steaming sounds good, but I'm pretty sure I would loose a good amount of aroma...
Kinda liked the "iced tea" idea I also make wine and use campden often – why wouldn't I think about it!
On the other hand, vodka should extract more flavor – I guess if I could get away with small amount (3~4 oz) of vodka somehow, it would be a great option. Maybe compact/crush the leaves with vodka, to make sure they get saturated...(?)

 

[Aaron Beers]

On the other hand, vodka should extract more flavor – I guess if I could get away with small amount (3~4 oz) of vodka somehow, it would be a great option.

If you're really serious about getting a specific flavor, I'd suggest you taste test 4 preparations:

1. Cold water, long extraction time
2. Cold alcohol, long extraction time
3. Hot water, short extraction time
4. Hot alcohol, short extraction time

Generally, the purpose for soaking plant material in alcohol is to allow for oils in that plant material to mix into the alcohol. Miscibility is the ability for two liquids to mix into a solution. Oil and water are not miscible. Oil and alcohol can be miscible to varying degrees based on the type of oil, type of alcohol, and other factors (most significantly, temperature).

It's not a given that the flavor you liked in the beer you tried came from the oils, and hence it's not clear that alcohol would be a better choice than water. It's also not clear whether the flavor you liked was based on a hot or cold process. I'd suggest you test both those variables before adding it to beer.

Also, the miscibility of oil and ethanol is not only highly dependent upon temperature, but also on the purity of the ethanol. Vodka is generally only 40% ethanol, and 60% water, which may prevent the vodka and oil from being miscible, even at very high temperatures (e.g. above the alcohol boiling point, under pressure). The best you're going to get (without your own still and breaking the law) is "grain alcohol" which will generally be 70-80% alcohol and likely carried at a liquor store near you. It's still possible that whatever oils are in birch leaves will not be significantly miscible with a 70-80% ethanol solution, but it will work exponentially better than vodka.

 

[user 214470]

I might try those 4 methods out of curiosity (a few leafs in each one).

I actually have some 95-99% medicinal alcohol, might try to use that one...

 

[Aaron Beers]

If by medicinal alcohol, you mean isopropyl alcohol, don't. That's not for consumption.

 

[user 214470]

No, I think it's ethanol. I have isopropyl but I only use it for cleaning stuff, definitely not drinking it